Intratumoral therapies of prostate cancer include the delivery of brachytherapy or ablation energy sources, and adenoviral injection, through a minimally invasive, transperineal approach. They require quantitative, optimized treatment planning, precise placement of the needles/probes according to the treatment plan, and real time dosimetric evaluation in the operating room as deviations from the treatment plan are detected. Recent studies suggest that imprecisions in standard brachytherapy using the manual technique cause higher than previously appreciated complication rates, and may be the cause of local failure in 15% of the patients. The major goal of the proposed work is to develop the Robot-Assisted Platform for Intratumoral Delivery (RAPID) for integrated treatment of prostate cancer, and to demonstrate the safety, efficacy and clinical effectiveness through bench/phantom tests and a Phase I clinical study. A number of maturing component technologies previously developed by the bioengineering research partners will be combined in this major collaboration, including the first robotic system for urological applications with early experience on actual patient treatment, the first treatment planning system with intraoperative dosimetry optimization, and the first needle/probe tracking system for real time ultrasound-based treatment verification, permitting re-planning and re-optimization of therapy delivery. The integrated RAPID system, designed based on prototype subsystems developed at each of the research partners, will initially focus on interstitial brachytherapy of prostate cancer. It is aimed at delivering precise, non-coplanar 3D conformal radiation rapidly and with assured consistency, and to incorporate such complex concurrent therapies as radiosensitization and mixed agent/strengths brachytherapy. Primary outcome variables including implant quality, cost, morbidity and learning curve will be examined under the clinical study by comparison with historical controls. The long-term objective of the RAPID project is to incorporate the delivery of concomitant therapeutic agents intratumorally for cancer in the prostate as well as in other organ systems. The multi-agent, multi-modality capabilities of the RAPID system will be continually exploited towards total optimization of a turnkey in vivo diagnosis and therapy engine for localized cancers of solid organs.